1. Technical Field
The present invention relates generally to a high-voltage wideband pulse load, and, more particularly, to a high-voltage wideband pulse termination load which has the wideband frequency performance of a high-voltage pulse.
2. Description of the Related Art
FIG. 1 is a view illustrating a prior art high-voltage load.
As shown in FIG. 1, a high-voltage load 10 includes a plurality of ceramic resistive elements 11 which are arranged in a stacked structure on a coaxial line, and includes a cable termination device 12 which terminates input impedance to 50 ohm.
The high-voltage load 10 includes an HN connector 13 which functions as an input terminal, and includes a dielectric substance 14 which is composed of oil in order to have insulation resistance.
Such a ceramic resistive element 11 is physically 1 inch long. The oil is not treated inside the ceramic resistive element, and a space between an internal electrode, which forms a high-voltage potential, and an earth line is filled with air.
However, since the internal diameter and external diameter of the high-voltage load 10 are designed to correspond to specific impedance, the external diameter of the HN connector 13 is not large enough to have high-voltage insulation resistance because of the restricted internal diameter. Therefore, when a pulse of dozens of kV is received, a dielectric breakdown phenomenon may occur in the HN connector 13. Further, since the gaps of the ceramic resistive elements 11 which are connected in parallel are filled with air, a dielectric breakdown may occur because of the corona phenomenon which is generated at high voltage.
As described above, there is a problem because it is difficult to use the prior art high-voltage load 10 as a high-voltage pulse load.
FIG. 2 is a view illustrating a prior art coaxial cable load.
As shown in FIG. 2, the coaxial cable load 20 is configured in such a way that the radius of the external housing 22 which covers a central electrode 21 gradually decreases such that the impedance of a coaxial line gradually decreases in a longitudinal direction, and that a resistive material 24 is deposited on the surface of a dielectric substance 23 in order to form a sheet resistor.
In the coaxial cable load 20, heat energy which is absorbed into the sheet resistor is easily transmitted to the external housing 22 which has a good thermal radiation metal structure, so that the heat energy may be air-cooled and annihilated.
The key idea of the coaxial cable load 20 in the aspect of structural characteristic is that of deposited sheet resistance on the surface between dielectrics and external housing, but has the problem in that it is difficult to deposit the sheet resistor regularly having wanted specific impedance, thereby being difficult to implement target impedance accurately.
As described above, in order to implement a termination load of an operational frequency domain of several GHz or higher and a high-voltage pulse of dozens of kV, both wideband frequency performance and high insulation voltage performance should be satisfied at the same time. However, since the characteristics of the two performances conflict with each other, it is difficult to solve the problem using the prior art technology.